hackage-packages.nix: update Haskell package set

This update was generated by hackage2nix v20151217-3-gd4ae18a using the following inputs:

  - Nixpkgs: https://github.com/NixOS/nixpkgs/commit/579e6bb79700b1c69c7e3afbb351a2f259b4435b
  - Hackage: https://github.com/commercialhaskell/all-cabal-hashes/commit/e1530f9f9a7c2ae7a710487d0ac66433e7f18bd7
  - LTS Haskell: https://github.com/fpco/lts-haskell/commit/d3e5ae70f97caffd4362b1511f3a2edfdc8a493d
  - Stackage Nightly: https://github.com/fpco/stackage-nightly/commit/db90cf927d67d362ead3be5a57b2ea84463ae83b